code.txt

偏微分方程的松弛迭代法

  import   java.text.*;   
  public   class   d16r1   
  {   
  public   static   void   main   (String[]   args)   
  {   
  //program   d16r1   
  //driver   for   routine   sor   
  int   jmax,   i,   j,   midl;   
  double   pi,   rjac,   aaa;   
  double   a[][]   =   new   double[12][12];   
  double   b[][]   =   new   double[12][12];   
  double   c[][]   =   new   double[12][12];   
  double   d[][]   =   new   double[12][12];   
  double   e[][]   =   new   double[12][12];   
  double   f[][]   =   new   double[12][12];   
  double   u[][]   =   new   double[12][12];   
  d16r1F   g   =   new   d16r1F();   
  DecimalFormat   form   =   new   DecimalFormat("0.00");   
  jmax   =   11;   
  pi   =   3.1415926;   
  for   (i   =   1;   i   <=   jmax;   i++)   
  {   
                          for   (j   =   1;   j   <=   jmax;   j++)   
  {   
                                  a[i][j]   =   1.0;   
                                  b[i][j]   =   1.0;   
                                  c[i][j]   =   1.0;   
                                  d[i][j]   =   1.0;   
                                  e[i][j]   =   -4.0;   
                                  f[i][j]   =   0.0;   
                                  u[i][j]   =   0.0;   
                          }   
  }   
  midl   =   jmax   /   2   +   1;   
  f[midl][midl]   =   2.0;   
  rjac   =   Math.cos(pi   /   jmax);   
  g.sor(a,   b,   c,   d,   e,   f,   u,   jmax,   rjac);   
  System.out.println();   
  System.out.println("sor   Solution:");   
  System.out.println();   
  for   (i   =   1;   i   <=   jmax;   i++)   
  {   
          for   (j   =   1;   j   <=   jmax;   j++)   
                          System.out.print(form.format(u[i][j])   +   "     ");   
          System.out.println();   
  }   
  System.out.println();   
  System.out.println("Test   that   sulotion   satisfies   Difference   Eqns:");   
  System.out.println();   
  for   (i   =   2;   i   <=   jmax   -   1;   i++)   
  {   
  for   (j   =   2;   j   <=   jmax   -   1;   j++)   
  {   
  aaa   =   u[i   +   1][j]   +   u[i   -   1][j]   +   u[i][j   +   1]   +   u[i][j   -   1];   
  f[i][j]   =   aaa   -   4.0   *   u[i][j];   
  }   
  for   (j   =   2;   j   <=   jmax   -   1;   j++)   
  System.out.print(form.format(f[i][j])   +   "     ");   
  System.out.println();   
  }   
  }   
  }